Control pump speed using PWM. Uses TM1638 keypad/display. Use it to start your PWM project!
This project uses the STM8S103P3 on a cheap Ebay board and a TM1638 display and keypad (8 key) module. The PWM output is on pin A3 (can be changed to D4). The power circuit (not included here) includes a IRLZ24 MOSFET transistor, which accepts a logic level (5 volts) input on its gate.
You can see photos of the circuit and the displays in the WIKI section.
There is a main display that shows the Off/Run status and the PWM percentage, from 0 to 100. There is another display that show the total run time, up to 9999 hours. A third display shows the ON and OFF cycle times. You can use the cycle feature if your motor won't function at low PWM values.
- S1: Choose OFF mode.
- S2: Choose RUN mode.
- S3: Switch between status and run time display.
- S4: Subtract 10% from PWM.
- S5: Add 10% to PWM.
- S6: (status display) Run pump for 60 seconds, then stop.
- S6: (hours display) Hold 2 seconds to reset run time to zero.
- S7: Subtract 1% from PWM.
- S8: Add 1% to PWM.
The configuration items are in pwm_pump.h in case you wish to change something.
This project uses SDCC to compile and my stm8_libs library. Please install that first. The Makefile expects stm8_libs and header files in ../libs, change for your layout.
Feel free to use this as a working prototype to develop your own application.
I have added the compiled image so you can just program the STM8S103 if you would like to try it before setting up the compiler and libraries.
You may contact the author at: richard@hodges.org I am available for embedded projects, large or small.